This research project is concerned with measurement of the optic cup (volume, area, and other topographical shape characteristics) through photogrammetric processing of stereo photographs of the optic nerve head. A digital image processing computer is being used to analyze pairs of stereo photographs to determine 3-dimensional characteristics of the optic cup from this information. A series of algorithms have now been developed to eliminate the effects of various photographic artifacts and provide sensitive, reproducible measurements of the optic cup. Approximately 120 patients with glaucoma or ocular hypertension are being examined over a period of five years to determine if this image processing technique can be used as an objective, highly sensitive indicator of the earliest glaucomatous damage to the optic cup. The sensitivity of this procedure for determining progression of glaucomatous damage to the optic cup is also being evaluated. All patients in the study receive extensive visual field testing and clinical optic disc evaluations in order to compare results of this new technique with standard clinical procedures for examining glaucoma.